Electric switch.



T. E. MURRAY 1 W. T. DEMPSBY. ELECTRIC SWITCH.

APPLIOATION FILED JULY 1, 1911.

1,01 1,639. 1 Patented Dec. 12,1911.

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THOMAS E. MURRAY AND WILLIAM T. DEMPSEY, OF NEW YORK, N. Y.

ELECTRIC SWITCH.

Specication of Letters Patent.

Application led July 1, 1911.

Be it known that we, THOMAS E. MUnRAY and WILLIAM T. DnMrsnY, citizens of the United States, residing at New York, in the Ycounty of New York and State of New York, have invented a certain new and use ful Improvement in Electric Switches,l of which the following is a specification.

The yinvention is an electric switch designed more particularly for heavy currents, and for use with arc lamps in series. The

Aconstruction is such as to secure, first, the

formation of a conducting path for the current to the lamp, and then the closing of circuit through said path, thus insuring the proper cutting of the lamp into circuit, and

out of same. LThis is effected by means of a simple lgang plug, which can be handled with perfect safety, without skilled manipw lation, and which can be inserted only in the proper position.

In the accompanying drawings-Figure 1 is a vertical section of our switch, on the linea, m of Fig. 3, showing the gang plug in place. Fig. 2 is a top View with the cover in place and gang plug removed. Fig. 3 is a section on the line y, y of Fig. 1. Fig. 4 is a section on the line e, e of Fig. 3, the gang plug being removed. Fig. 5 is a side elevation, andFig. 6 an edge elevation, of thev gang plug.

Similar numbers of reference indicate like parts.

The cup-shaped base 1l of the: device is preferably made of refractory insulating "material, and is provided with side brackets 2, through the vertical portions of which are formed openings 3, to receive bolts (not shown) by which said base may be secured to a post or other suitable support. In the horizontal portions of the brackets 2 are openings whichreceive the bolts 4, by means of which the cover 5, also of refractory in-l sulating material, `is secured to the base 1.

The base is internally divided vinto two compartments 6, 7, by means ofthe part-i-` tion 8. AIn compartment' are 'two cont-act clips 9, 10, and in compartment 7 .are two similar clips 13, 14. Each clip.v at its lower portion is bent twice on itself 'at right angles, so that a vertical portion a stands parallel to the vertical portion b. The end c of the portion a. is curved overand downwardly, parallel to portion b, and the free extremity d of said end rests on a projection 11 on the bottom of the compartment. The

from saidv clips to the corresponding end portions c of the clips are normally in contact. The upper end of each clip l9, 10 is bent at right angles inwardly and then folded back on itself, vand through both parts a threaded opening is formed, to receive a binding screw 12. The clips 13, 14 are provided with similar binding screws 12 at their upper ends. In the portion b of each clip is formed a tongue 16, Fig. 4, which, when the clip is seated inc the base, is forced outwardly to engage in a notch made in the wall of the base, these tonguesf then holding the clips in place.

The main circuit conductors 17, 18 eX- tend up through openings formed in the Wall of the base 1, and areV connected to contact clips 9, 10, 'by means of the: binding screws 12. The local conductors 19, 2O are connected to the contact clips 13, 14 by binding screwsf12x, and pass out of the base through a notch 21 formed in the upper edge thereof. Said local conductors may be connected to a translating device, such as an arc-lamp, symbolically indicated at 22, Fig. 3.

The gang plug, Figs. 5 and 6, is inserted through ank opemng 23 in the cover 5. The handle 24 is formed of two plates of insulating material connected by screws 25,

and receiving between them two bifurcated plates of metal, 26, 27 separatedn by a late of insulating material 28.` One leg e .o the double plug thus produced is made shorter than the other leg f. The vcross section of the handle, where it enters the opening 23, is made wedge-shaped, to suit the shape of said opening, and 1s provided with a flange which extends over the cover and receives 1n a suitable groove a rib 29 surrounding said opening. The rib serves as a dam to prevent the entrance of water around the joint between handle and base.

The gang plug is inserted, so as to bring the long leg f between the clips 14, 13 and the short leg e between the clips 9, 10. The object of making thecover opening 23 and the handle wedge-shaped, is to insure the proper placing of the plug in this respect. Circuit then proceeds from main conductor 18, to clip 10, plate 27, clip 13, by local conductor 20, to lam 22, and return by local conductor 19, to cip 14, plate 26, clip 9 and main conductor 17.

It will be obvious that when the plug is inserted, thelong'leg f enters the clips 13, 14, and so establishes a ath for the current llaimp, before the short leg e' enters clips 9, l0, and so closes circuit through said path.

The base may be filled with oil, as shown at 30, Fig. et, in order to protect the contacts therein in the usual way. The artition 8 being of 'insulating material, Forms a barrier preventing leakage or sparking across from one pair of contact clips to the other.

IVe claim:

l. An electric switch, comprising a base, two pairs of contacts therein, circuit terminals respectively connected to the members of said pairs of contacts, and a bifurcavted gang plug, having legs of unequal length, entering said pairs of contacts and connecting one member of each pair of contacts with the corresponding member of the other palr.

2. An electric switch, comprising a base,

- two pairs of contacts therein, circuit terminals respectively connected to the members of said pairs of contacts, a biu'rcated gang plug, having legs of unequal length, entering said pairs of contacts and connecting one member of each pair of contacts with the corresponding member of the other pair, and means for determining the insertion of the longer leg only in a selected pair of said contacts.

8. An electric switch, comprising a cupshaped base, a partition dividing the same into two compartments, a pair of contact clips in each compartment, clrcuit terminals res ectively connected to the members of sai pairs of clips, and a bifurcated gang plug, having legs of unequal length, entering said pairs of clips and connecting one member of each pair of clips with the cor- A responding member of the other pair.

4. An electric switch, comprislng a cupshaped base, two pairs of contacts therein, circuit terminals respectively connected to the members of said pairs of contacts, a bifurcated gang plu having a handle of insulating material, ifurcated arms entering said pairs of contacts and connecting one member of each pair of contacts with the corresponding member of the other pair, and a cover having an opening receiving said handle; the said cover opening and handle being of corresponding cross section, and of a shape preventing the insertion of said handle in said opening otherwise than in one position. f

In testimony whereof we have atlixed our signatures in presence of two Witnesses.

THOMAS E. MURRAY. WILLIAM T. DEMPSEY. Witnesses:

GERTRUDE T. PORTER, MAY T. MCGARRY. 

